topic Re: Canon mount dapter eos ef R vignettes in Camera Accessories

Mount Adapter EF-EOS R vignettes terribly

clifff27 — Tue, 23 Jul 2024 13:46:16 GMT

Canon RP camera with adapter. Sigma 18-200 vignettes terribly so that picture is an oval surrounded by black. If shooting at 200 it is fine, but anything less vignettes. Same with Tamron. Is this to be expected? If so the adapter is useless...Thanks

Re: Canon mount dapter eos ef R vignettes

kvbarkley — Thu, 20 May 2021 15:49:31 GMT

Which Sigma 18-200? Is it the EF-S version?

Is it the Canon Adapter?

Note that all the adapter does is put the lens at the same physical location it would be on an EF/EF-S camera, so it should not vignette any more than the lens on an EF or EF-S camera.

Re: Canon mount dapter eos ef R vignettes

rs-eos — Thu, 20 May 2021 16:58:02 GMT

Sounds like your Sigma lens may be EF-S (designed to work with crop-sensor cameras). But the RP is full frame so the lens' image circle isn't large enough to cover the entire sensor.

Re: Canon mount dapter eos ef R vignettes

clifff27 — Thu, 20 May 2021 17:11:19 GMT

It is the standard Canon adapter...Lens is Sigma DC 18-200 with Canon mount. Not sure if EF or EF S... Used with D80 and no problem...Vignette problem is 18-150

Have a Tamron SP 10-24 same problem. Vignette from about 10-16.

Tamron 200-500 seems fine.

Canon ef 28-80 is also fine.

Re: Canon mount dapter eos ef R vignettes

rs-eos — Thu, 20 May 2021 17:15:36 GMT

A D80 is a crop-sensor camera.

No doubt, wide angle lenses as well as wide aperture lenses (e.g. EF 50mm f/1.2L) will vignette. But as mentioned earlier, if you are using a lens on your full-frame camera that was desgined for a crop (smaller) sensor camera, that will really add to amount of vignetting. And entire portions of the corner of the image may also now be completely black since not possible for any light to reach that area.

Re: Canon mount dapter eos ef R vignettes

clifff27 — Thu, 20 May 2021 17:19:10 GMT

Disappointing that this has happened...read numerous reviews of the adapter and do not remember this being mentioned as a problem...

Re: Canon mount dapter eos ef R vignettes

rs-eos — Thu, 20 May 2021 17:44:08 GMT

It's not the adapter. Please re-read the answers you got above. Also, you'll want to find out if your lens is EF-S or not. I suspect it is. If so, that's the issue.

Re: Canon mount dapter eos ef R vignettes

Waddizzle — Thu, 20 May 2021 17:47:47 GMT

@clifff27 wrote:
Disappointing that this has happened...read numerous reviews of the adapter and do not remember this being mentioned as a problem...

The problem is not the mount adapter. It is the lenses. Canon EF-S lenses cause the camera to automatically enter a crop mode. Somehow the camera senses the EF-S lens through the adapter and it "adapts" itself into a crop mode.

Apparently, this is not automatically taking place with your third party lenses. The cause must be due to the fact that even though lens circle is for a crop sensor body, many third party lens manufacturers use only one lens mount for both full frame and APS-C lenses.

Of course the one lens mount they tend ot use is for full frame lenses. It works on both types of bodies. I would speculate that the camera thinks there is a full frame lenses mounted to it, so it is notautomatically going into crop mode.

Re: Canon mount dapter eos ef R vignettes

clifff27 — Thu, 20 May 2021 19:39:16 GMT

thank you..all is well...just need to save for a full frame lens...

Re: Canon mount dapter eos ef R vignettes

ebiggs1 — Fri, 21 May 2021 15:16:02 GMT

I believe the DC name is Sigma’s note for crop sensor cameras. DN is for mirrorless.
I can’t remember mounting a DC on my FF body so I don’t know if it will.

Re: Canon mount dapter eos ef R vignettes

Waddizzle — Fri, 21 May 2021 19:47:30 GMT

@ebiggs1 wrote:
I believe the DC name is Sigma’s note for crop sensor cameras. DN is for mirrorless.
I can’t remember mounting a DC on my FF body so I don’t know if it will.

Canon uses a red dot for EF lens mounts, and a white square for EF-S lens mounts. Sigma uses neither. Sigma uses a white dot that aligns with Canon's red dot on a camera body. All of their lenses are made this way.

Re: Canon mount dapter eos ef R vignettes

Waddizzle — Fri, 21 May 2021 19:52:01 GMT

Sigma 18-200mm. Notice the white dot, which aligns with the Canon red dot.

Why spend the extra money to make two diffferent mounts, when using just one gets the job done?

Re: Canon mount dapter eos ef R vignettes

ebiggs1 — Fri, 21 May 2021 21:14:50 GMT

"Why spend the extra money to make two diffferent mounts, when using just one gets the job done?"

Perhaps so, however, Sigma does indicate which camera model their lenses are designed for. DG is for full frame while DC is for the cropper series. DN is their new designation for mirrorless. Example my 120-300mm F2.8 DG OS HSM Sport is designed as a FF lens. Indicated by the "DG" in its name. Although it will mount on a cropper and perform flawlessly.

I have not, or at least I can't ever remember doing so, mounted a DC lens on any of my FF cameras. I would hope that people would realize it is not the best idea and specifically why Sigma makes the name different for each line. I actually don't ever think I have owned any EF-S/DC lenses at all. I have used a very few but I don't remember owning any. They are just not built well enough to satisfy my requirements.

Re: Canon mount dapter eos ef R vignettes

jrhoffman75 — Sat, 22 May 2021 00:37:24 GMT

Only Canon lenses have an EF-S mount. All third party lenses use the EF mount, but if they are designed for the APS-C bodies they will usually vignette at the wider focal lengths.

Re: Canon mount dapter eos ef R vignettes

hothrt — Tue, 15 Mar 2022 02:15:19 GMT

Today I was shooting birds and the vignetting is horrible even at 200mm.

Canon EOS R6 with the basic adapter and the Canon EF 70-200

Re: Canon mount dapter eos ef R vignettes

p4pictures — Sun, 29 May 2022 21:45:07 GMT

This problem is caused by the Sigma lens. Several of the lenses from Sigma / Tamron and other independent makers were designed for APS-C crop sensor cameras and sold as such. However the manufacturer didn't make the lens tell the camera that it was an APS-C lens, Canon EF-S lenses do tell the camera that they are APS-C lenses.

As such, the EOS RP with mount adapter sees a lens, doesn't get info from the lens that it is a crop lens so the camera shoots as a full-frame camera. The result is vignetting / circular images to some effect. I wrote about that here on my blog https://www.p4pictures.com/2019/06/eos-r-crop-lenses-aps-c/

Canon EF-S lenses fitted to the adapter do tell the camera they are crop lenses, and so the camera automatically selects the 1.6x crop mode and it cannot be deselected.

Re: Canon mount dapter eos ef R vignettes

paigegreen0004 — Sun, 21 Jul 2024 00:37:27 GMT

I was having a similar problem. This was extremely helpful and solved my problem - thank you!

Re: Canon mount dapter eos ef R vignettes

EveH — Sun, 28 Jul 2024 14:10:56 GMT

Thanks for this! It will get me by while I save up for the FF lens. I appreciate the education on the lens types and why I'm getting the vignette with the adapter.

Re: Mount Adapter EF-EOS R vignettes terribly

Maximizedjones — Thu, 19 Sep 2024 09:46:45 GMT

Thanks for the great article and post. It was very helpful in helping me to understand why I was experiencing the vignette issue with my Tamron lenses on my Canon RP with the EF to EOS R adapter.